"O.T.T.O's home and the main building of the second stage. May contain additional feisty robots. Destroying O.T.T.O's Outpost awards an extra star in attacks."
| Level | Hitpoints | Spawned zappies | Build cost | Build time | Experience gained | Builder hall level required |
|---|---|---|---|---|---|---|
| 1 | 650 | 2 | N/A | N/A | N/A | 6 |
| 2 | 800 | 2 | 1,000,000 | 1d | 293 | 6 |
| 3 | 975 | 2 | 1,250,000 | 2d | 415 | 6 |
| 4 | 1,150 | 3 | 1,500,000 | 3d | 509 | 6 |
| 5 | 1,350 | 3 | 1,750,000 | 4d | 587 | 6 |
| 6 | 1,600 | 3 | 2,000,000 | 5d | 657 | 6 |
| 7 | 1,850 | 4 | 3,000,000 | 7d | 777 | 7 |
| 8 | 2,150 | 4 | 4,000,000 | 9d | 881 | 8 |
| 9 | 2,450 | 4 | 5,000,000 | 10d | 929 | 9 |
| 10 | 2,750 | 5 | 6,000,000 | 11d | 974 | 10 |
Tapping this icon displays information about your inventory ofMagic Items.
Tapping this icon allows you to change between anySceneriesthat you have unlocked.
Tapping this icon begins upgrading the O.T.T.O's Outpost to the next level, if you have enough resources and a freeMaster BuilderorO.T.T.O. When the O.T.T.O's Outpost is at maximum level, this icon is not shown.
Tapping this icon instantly upgrades the O.T.T.O's Outpost to the next level, at the cost of oneHammer of Buildingif you have one. When the O.T.T.O's Outpost is at maximum level, or theBuilder Hallrequirements for the next level are not met, this icon is not shown.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of the displayed number ofGems.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of oneBook of Building. This icon is only shown if you have at least one Book of Building.
Tapping this icon, which is displayed only while an upgrade is in progress, instantly finishes that upgrade at the cost of oneBook of Everything. This icon is only shown if you have at least one Book of Everything but do not have a Book of Building.
Tapping this icon, which is displayed only while an upgrade is in progress, cancels the current upgrade and refunds half of the upgrade cost.